1. Field of the Invention
The present invention relates to a cathode active material for non-aqueous electrolyte rechargeable secondary batteries.
2. Description of the Related Art
Metal fluorides represented by a general formula MF3, for example, are known to be used as cathode active materials for non-aqueous electrolyte rechargeable secondary batteries which are used for driving power sources of electric vehicles. (For example, refer to Japanese Patent Laid-Open No. 2008-130265.)
M in the general formula MF3 is one type of a metal element selected from the group consisting of Fe, V, Ti, Co, and Mn. The metal fluorides represented by the general formula MF3 are known to have a high theoretical energy density (reversible capacity). For example, a non-aqueous electrolyte secondary battery containing FeF3 as a cathode active material and Li as an anode active material is considered to have a theoretical energy density of about 240 mAh/g.